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The amphiphilic copolymer polystyrene-maleic anhydride (SMA)-2-hydroxyethyl acrylate (HEA) was synthesized for the first time in this study, and used as a linker to graft zwitterionic sulfobetaine methacrylate (SBMA) in order to enhance the hydrophilicity and anti-adsorption ability of polyvinylidene difluoride (PVDF) membranes. This amphiphile linker is composed of a hydrophobic extremity, i.e., the SMA copolymer, and a hydrophilic extremity, i.e., the HEA. The SMA-HEA linker was first dispersed into the PVDF matrix via the blending method, and the hydrophobic polystyrene of SMA was adsorbed into the PVDF membrane via hydrophobic–hydrophobic interaction. The SBMA was then grafted onto the expanded HEA via free radical polymerization. The functional groups, morphologies, and hydrophilicity of the amphiphile-modified PVDF membranes were analyzed by attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR), field emission scanning electron microscopy (FE-SEM), and water contact angle (WCA) measurements. The PVDF membrane modified with the SMA-HEA amphiphile linker showed significant enhancement in hydrophilicity as the WCA decreased from 135.0° to 45.0°, and the protein adsorption of the modified membrane decreased from 112.5 to 33.3 μg⋅cm−2. Furthermore, dynamic protein separation was performed, and the pure water flux recovery rate reached 100%, indicating good anti-adsorption ability.

7-Aminoquinoline (7AQ) and various amino derivatives thereof (-NHR) have been strategically designed and synthesized to study their excited-state proton-transfer (ESPT) properties. Due to the large separation between the proton donor -NHR and the acceptor -N- site, ESPT in 7AQ derivatives, if available, should proceed under protic solvent catalysis. ESPT is found to be influenced by the acidity of -NHR and the basicity of the proton-acceptor -N- in the quinoline moiety. The latter is varied by the resonance effect at the quinoline -N- site induced by the -NHR substituent. For those 7AQ derivatives undergoing ESPT, increased quinoline basicity results in a faster rate of ESPT, implying that proton donation from methanol to the quinoline moiety may serve as a key step in the process. Our studies also indicate the existence of an equilibrium between cis and trans arrangements of -NHR in terms of its hydrogen-bond (H-bond) configuration with methanol, whereby only the cis-H-bonded form undergoes methanol-assisted ESPT. With one exception, the interconversion between cis and trans configurations is much faster than the rate of ESPT, yielding amino-type (normal form) and imine-type (proton-transfer tautomer) emissions with distinct relaxation dynamics.

Antibiotics are commonly used as inhibitors to terminate protein formation in the biotechnology and pharmaceutical industries; however, due to the large difference in molecular weight between antibiotics and proteins, it is hard to remove them simultaneously through ultrafiltration or nanofiltration. In this work, a novel membrane with nanoscale pores and anti-protein adsorption was developed to reject antibiotics and reduce protein adhesion. Amphiphiles consisting of hydrophobic and hydrophilic moieties were synthesized from a poly(styrene-alt-maleic anhydride) (SMA) copolymer with a 2-hydroxyethyl acrylate (HEA) monomer to enhance the hydrophilicity of polyvinylidene difluoride (PVDF) membranes. A series of SMAs with different polystyrene molar ratios (maleic acid/styrene (m/s) = 1:1, 1:2 and 1:3) was synthesized in this study, and the bonding force between the amphiphiles and PVDF, namely, π-π interactions between styrene molecules and the C–F bonds of PVDF, was evaluated. The π-π interaction between the amphiphiles and the PVDF membrane was determined via atomic force microscopy (AFM) repulsive force measurements for the first time in this work. The repulsive force increased significantly from -5.9 ± 1.0 nN to −18.3 ± 0.8 nN as the m/s ratio increased to 1:3, indicating that the π-π interaction was enhanced as the proportion of polystyrene in the SMA-HEA copolymer increased, resulting in tight attachment. Furthermore, the amphiphile-modified membrane demonstrated better hydrophilicity than the pristine PVDF membrane, and the water contact angle (WCA) decreased considerably from 104° (PVDF) to 55° (m/s = 1:2, P2000-600). The pure water flux recovery rate of P2000-600 improved by approximately 10%, and antibiotic rejections of 92.8%, 99.9% and 97.1% for tetracycline (TC), chloramphenicol (CL) and erythromycin (EM), respectively, were observed during the 7-h filtration process, indicating that P2000-600 can effectively remove antibiotics from water. In addition, P2000-600 also displayed good restriction of bovine serum albumin (BSA) adsorption at 28.4 ± 8.1 μg/cm2 under static adsorption processes and BSA rejection of nearly 90% during the three-cycle filtration.

The fouling caused by protein ultrafiltration is a bottleneck during wastewater treatment in the biotechnology industry. In this study, the antifouling and mechanism of superior protein rejection by a branch-like structure of zwitterions grafted onto a PVDF membrane via a novel amphiphilic linker is reported. The SMA-HEA amphiphilic linker, 2-hydroxyethyl acrylate-terminated poly(styrene-alt-maleic anhydride) (SMA-HEA), consisting of a hydrophobic poly(styrene-alt-maleic anhydride) (SMA) alternating copolymer and a hydrophilic 2-hydroxyethyl acrylate (HEA) monomer, was first synthesized in this study by a ring-opening reaction. The hydrophobic styrene unit of SMA-HEA was first adsorbed onto the PVDF surface via hydrophobic-hydrophobic adsorption, and then the C C bond of HEA was anchored to graft sulfobetaine methacrylate (SBMA) zwitterions via thermally induced free-radical polymerization using 2,2′‐azoisobutyronitrile (AIBN) as the initiator. The effects of the hydrophobic adsorption and free-radical polymerization time on membrane characteristics, such as the hydrophilicity, pore size distribution, static protein adsorption, antifouling and flux recovery rate were analyzed. The modified membrane possessed a superior water contact angle (WCA), which decreased from 130° to 24.9°, and the protein absorption decreased from 112.5 to 4.2 μg cm−2. The degree of polymerization of SBMA and the mechanism of the SMA-HEA-linked PVDF membranes were determined by Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA), and a branch-like zwitterionic structure of the modified membrane was proposed. It was shown that the best pure water flux recovery rate of the modified PVDF membrane was significantly enhanced from 42.5 to ca. 100% with over 90% protein rejection. This self-designed and synthesized SMA-HEA linker had great potential for the surface modification of hydrophobic membranes.

Studies have been carried out to gain insight in to an overall excited-state proton transfer cycle for a series of N-tosyl derivatives of 2-(2'-aminophenyl)benzothiazole. The results indicate that followed by ultrafast (

A novel α-ethoxynaphthalene-dicyanovinyl conjugate 1 with an intramolecular charge transfer (ICT) characteristic was synthesized for the highly selective and reactive detection of CN− in a wide pH range of 3–10. The colorimetric and fluorometric response of the sensor to CN− is attributable to the addition of CN− to the β-conjugated position of the dicyanovinyl group of 1, which blocks ICT. The sensing mechanism is supported by 1H NMR titration experiments and density functional theory (DFT) calculations. Moreover, chemodosimeter 1 shows strong yellow fluorescence in the solid-state, and 1-based test strips can be easily prepared at low-cost and can be used in practical and efficient test kits for CN− detection. The results provide the proof of concept that the ICT-based colorimetric and fluorometric cyanide-selective chemodosimeter can be created based on a simple alkoxy-substituted small molecule.

Flexible gelatin resistive memory device exhibits a high ON/OFF ratio of over 106. Moreover, the bended gelatin resistive memory device can efficiently heal at room temperature without any external stimulus. This self-healing behavior of gelatin resistive memory device was demonstrated based on the metal chelating ligand. Al ions migrating from the top radio frequency Al electrode contributed to the construction of the metal chelating ligand. The carboxylates of gelatin can form multi-dentate coordination compounds with Al ions, which can restore the memory properties of the gelatin resistive memory device. Thus, Al ion migration from the top Al electrodes plays an important role in self-healing capability. The effect of Al ions on the self-healing mechanism was investigated by using secondary ion mass spectrometry, which is useful for the characterization of Al migration from the top electrode. This capability for restoring the electrical properties of gelatin memory device is desirable for flexible electronics and represents a major step toward self-healable bioelectronics.

Enzymatic syntheses of fatty acid anilides are important owing to their wide range of industrial applications in detergents, shampoo, cosmetics, and surfactant formulations. The amidation reaction of Mucor miehei lipase Lipozyme IM20 was investigated for direct amidation of triacylglycerol in organic solvents. The process parameters (reaction temperature, substrate molar ratio, enzyme amount) were optimized to achieve the highest yield of anilide. The maximum yield of palmitanilide (88.9%) was achieved after 24 h of reaction at 40 °C at an enzyme concentration of 1.4% (70 mg). Kinetics of lipase-catalyzed amidation of aniline with tripalmitin has been investigated. The reaction rate could be described in terms of the Michaelis-Menten equation with a Ping-Pong Bi-Bi mechanism and competitive inhibition by both the substrates. The kinetic constants were estimated by using non-linear regression method using enzyme kinetic modules. The enzyme operational stability study showed that Lipozyme IM20 retained 38.1% of the initial activity for the synthesis of palmitanilide (even after repeated use for 48 h). Palmitanilide, a fatty acid amide, exhibited potent antimicrobial activity toward Bacillus cereus.

A series of new amino (NH)-type hydrogen-bonding (H-bonding) compounds comprising 2-(2'-aminophenyl)benzothiazole and its extensive derivatives were designed and synthesized. Unlike in the hydroxyl (OH)-type H-bonding systems, one of the amino hydrogens can be replaced with electron-donating/withdrawing groups. This, together with a versatile capability for modifying the parent moiety, makes feasible the comprehensive spectroscopy and dynamics studies of amino-type excited-state intramolecular proton transfer (ESIPT), which was previously inaccessible in the hydroxyl-type ESIPT systems. Empirical correlations were observed among the hydrogen-bonding strength (the N-H bond distances and proton acidity), ESIPT kinetics, and thermodynamics, demonstrating a trend that the stronger N-H···N hydrogen bond leads to a faster ESIPT, as experimentally observed, and a more exergonic reaction thermodynamics. Accordingly, ESIPT reaction can be harnessed for the first time from a highly endergonic type (i.e., prohibition) toward equilibrium with a measurable ESIPT rate and then to the highly exergonic, ultrafast ESIPT reaction within the same series of amino-type intramolecular H-bond system.

Facile derivation of 10-aminobenzo[h]quinoline via replacing one of the N-H hydrogen atoms by various substituents generates a new series of excited-state intramolecular N-H proton-transfer molecules, for which the proton-transfer emission can be widely tuned from 590 nm to 770 nm simply by harnessing the electron-donating/withdrawing strength of the substituents.

Searching for eight-membered ring π-conjugated hydrogen bonding (8-MR H-bonding) systems with excited-state intramolecular proton transfer (ESIPT) property is seminal and synthetically challenging. In this work, a series of π-conjugated molecules (8-HB-1, 8-HB-L1 and 8-HB-2) potentially possessing 8-MR H-bonding are strategically designed, synthesized and characterized. The configurations of these three potential molecules are checked by their X-ray structures, among which 8-HB-L1 (a structurally locked 8-HB-1 core chromophore) is proved to be an 8-MR H-bonding system, whereas 8-HB-1 and 8-HB-2 are too sterically hindered to form the 8-MR intramolecular H-bond. The ESIPT property of 8-HB-L1 is confirmed by the dual fluorescence consisting of normal and proton-transfer tautomer emissions. The insight into the ESIPT process of 8-HB-L1 is provided by femtosecond fluorescence upconversion measurements together with computational simulation. The results demonstrate for the first time a successful synthetic route to attain the 8-MR H-bonding molecule 8-HB-L1 with ESIPT property.

A one-pot synthesis of symmetrical and unsymmetrical substituted thioureas and 2-imino-4-thiazolidinones from simple starting materials under microwave irradiation and solventless conditions without base additives is presented. Various di- and trisubstituted thioureas are obtained in good yields in a few minutes. The sequential, three-component, one-pot synthesis of 2-imino-4-thiazolidinone derivatives is also studied, with satisfactory results obtained.

We succeeded in developing a convenient one-pot pathway for synthesizing 4,4′-dimethoxy-boradiaza-s-indacene dyes 4a–d. The structures feature two methoxy groups in place of the fluorine atoms in 4,4′-difluoro-4-boradiaza-s-indacene. These novel dyes emitted green fluorescence and possessed moderate to high fluorescence quantum yields (Φ=0.32–0.93). We demonstrated that these dyes have applicability to cell labeling.

Capsaicin (8-methyl- N -vanillyl-6-nonenamide) is the main pungent component in capsicum fruits. Its analog, palmitoyl vanillylamide, with similar properties, was synthesized through amidation by lipase in supercritical carbon dioxide (SC–CO 2 ) and reaction conditions were optimized. Among five lipases tested, immobilized Mucor miehei lipase, Lipozyme IM, was most effective in synthesizing this analog. The reaction conditions for analog synthesis were optimized and were 50 °C, 17 MPa and pH 8 for 23 h using vanillylamine hydrochloride and palmitic anhydride at a molar ratio of 5/15 as substrates catalyzed by Lipozyem IM at a concentration of 0.5% (w/w). The residual enzyme activity was about 40% and 15% after a 46- and 69-h repeated amidation reaction in a batch reaction under optimized conditions, suggesting further modification of conditions was required.

Substrate oil composition, reaction time, acyl donor, temperature, and pressure affected the triacylglycerol (TG) content of cocoa butter analog during the interesterification reaction catalyzed by lipase in a supercritical carbon dioxide (SC-CO 2 ) system. Among oil sources used to interact with tristearin, the content of 1(3)-palmitoyl-3(1)-stearoyl-2-monoolein (POS) (P, palmitate; O, oleate; S, stearate) and 1-palmitoyl-2, 3-dioleoylglycerol (POO) in analog was most similar to the corresponding TG content of cocoa butter when analog was prepared with lard. The optimized interesterification reaction using lard and tristearin (at a mole ratio of 1.4) as substrates to produce cocoa butter analog in a SC-CO 2 system was at 17 MPa, 50 °C, pH 9, for 3 h with an immobilized lipase, Lipozyme IM-20, from Mucor miehei . The lyophilized enzyme facilitated the production of cocoa butter analog in anhydrous substrates ( a w 0.33). The yield and melting point of the purified cocoa butter analog by a silica column was 63% and 34.5 °C, respectively, when the analog was produced under optimal conditions.

We report a novel ‘fluorescent dopamine’ that possesses essential features of natural dopamine. Our method is simple and is readily extended to monoamine neurotransmitters such as L-norepinephrine, serotonin and GABA, providing a more practical approach. Because of its compatibility with sensitive fluorescent measurements, we envisage that our approach will have a broad range of applications in neural research.

The synthesis of thioureas (IV), (VI), (VIII), and (X) is performed under environmentally benign, neat conditions without the use of base additives.

The generation of alpha-carbonyl vinyl radicals from alpha-iodo cycloalkenones, the scope of their participation in intermolecular addition reactions with electron-withdrawing olefins are studied and a synthetic study of the formal synthesis of enantiopure fawcettimine using this reaction is described.

Triethylene glycol monomethyl ether and poly(ethylene glycol) monomethyl ether modified 2-(2'-aminophenyl)benzothiazoles, namely ABT-P3EG, ABT-P7EG and ABT-P12EG varied by different chain length of poly(ethylene glycol) at the amino site, were synthesized to probe their photophysical and bio-imaging properties. In polar, aprotic solvents such as CH2Cl2 ultrafast excited-state intramolecular proton transfer (ESIPT) takes place, resulting in a large Stokes shifted tautomer emission in the green-yellow (550 nm) region. In neutral water, ABT-P12EG forms micelles with diameters of 15 ± 3 nm under a critical micelle concentration (CMC) of ~80 μM, in which the tautomer emission is greatly enhanced free from water perturbation. Cytotoxicity experiments showed that all ABT-PnEGs have negligible cytotoxicity against HeLa cells even at doses as high as 1 mM. Live-cell imaging experiments were also performed, the results indicate that all ABT-PnEGs are able to enter HeLa cells. While the two-photon excitation emission of ABT-P3EG in cells cytoplasm shows concentration independence and is dominated by the anion blue fluorescence, ABT-P7EG and ABT-P12EG exhibit prominent green tautomer emission at > CMC and in part penetrate to the nuclei, adding an additional advantage for the cell imaging.

Radicals generated from 4-bromo vinylogous-esters, vinylogous-amides and enones cyclize to a tethered acetylene side-chain preferentially at the γ-position; theoretical calculations of the spin density of the radicals and the relative stability of the radical intermediates are performed to rationalize the experimental observations.

Humic acid (HA), a group of high-molecular weight polymer, resulting from the decomposition of organic matter has been implicated as a possible etiological factor for Blackfoot disease and cancer. In this study, we evaluate the promotion effect of HA on the transformation in mouse epidermal JB6 clone 41 (JB6 Cl41) cells that have been used to identify the tumor promoting activity of various compounds. Our preliminary assay demonstrated that JB6 Cl41 cells with the treatment of HA at the concentration of 100 μg/ml for 72 and 96 h significantly increased reactive oxygen species (ROS) as compared to the untreated control. In addition, the 48 h cultured cells with HA pretreatment for 48 h also increased ROS as compared to the untreated control. HA-pretreated cells develop highly scattered and spindle-shaped cells with few observable cell–cell contacts, and contain more filopodia. In vitro wound-healing assay showed that JB6 Cl41 cells with HA pretreatment increased the migrating growth. Furthermore, transformed foci of JB6 Cl41 cells following the HA pretreatment were observed after 6 weeks culture. In anchorage-independent growth assay, we found that HA promoted the colony formation and that colonies were inhibited by antioxidant N-acetyl cysteine (NAC). Our results suggest that HA may promote the transformation of epidermal cells and that this process is mediated by the generation of ROS.

The syntheses of three fused bicyclic enones, including 1,2,6,6a-tetrahydro-1-tosyl-cyclopenta[b]pyrrol-3(5H)-one, 1,2,3,6,7,7a-hexahydro-4H-1-tosyl-cyclopenta[b]pyridin-4-one and 1,2,5,6,7,7a-hexahydro-3H-1-tosyl-indol-3-one, via anionic cyclization and Diels-Alder reactions with various dienes to construct novel nitrogen-containing angular tricyclic skeletons are described.

Radicals generated from 4-bromo vinylogous-esters, vinylogous-amides and enones cyclize to a tethered acetylene side-chain preferentially at the γ-position; theoretical calculations of the spin density of the radicals and the relative stability of the radical intermediates are performed to rationalize the experimental observations.